Question

嗨，在我的应用程序中，我有UIImageView上的图像，我有一个名为下载的按钮，一旦用户点击下载按钮，图像将保存到Photolibrary。现在我想添加下载进度条以了解用户下载图像。

我已经使用MBProgressHUD来取得进展但却无法像我想要的那样工作。我想显示一旦用户点击下载按钮，如下载消息，一旦图像下载我想要显示图像下载，请告诉我如何实现这一个我厌倦了这样的事情。

我的MBProgressHUD代码。

- (IBAction)down:(id)sender {

   HUD = [[MBProgressHUD alloc] initWithView:self.view];
   HUD.labelText = @"downloading...";

   HUD.mode = MBProgressHUDModeAnnularDeterminate;
   [self.view addSubview:HUD];

   [HUD showWhileExecuting:@selector(download) onTarget:self withObject:nil animated:YES];

   UIImageWriteToSavedPhotosAlbum(imageview.image, nil, nil, nil);

 }

- (void)download {
float progress = 0.0;

while (progress < 1.0) {
    progress += 0.01;
    HUD.progress = progress;
    usleep(50000);
  }
}

我已经使用上面的代码来实现，但它不能像我想的那样工作，请告诉我如何实现这个。

感谢。

Answer 1

- (IBAction)down:(id)sender {



HUD = [MBProgressHUD showHUDAddedTo:self.view animated:YES];
HUD.mode =MBProgressHUDModeAnnularDeterminate;

NSString *strloadingText = [NSString stringWithFormat:@"Downloading...."];
HUD.labelText = strloadingText;


[HUD show:YES];

[HUD showWhileExecuting:@selector(doSomeFunkyStuff) onTarget:self withObject:nil animated:YES];



}


- (void)doSomeFunkyStuff {
float progress = 0.0;

while (progress < 1.0) {
    progress += 0.01;
    HUD.progress = progress;

    usleep(5000000);

    dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_LOW, 0),
                  ^{
                       // process in background thread
                      NSString *strloadingText = [NSString stringWithFormat:@"completed"];
                      HUD.labelText = strloadingText;UIImageWriteToSavedPhotosAlbum(imageview.image, nil, nil, nil);




                       [HUD hide:YES];


                   });

 }
}

Answer 2

UIImageWriteToSavedPhotosAlbum适用于主线程。所以，把这个功能放在GCD中。主线程忙时，您的UI无法自行更新。

Answer 3

试试这个：

- (IBAction)down:(id)sender {
...

[HUD showWhileExecuting:@selector(download) onTarget:self withObject:nil animated:YES];

dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_LOW, 0),
^{
        // process in background thread
        UIImageWriteToSavedPhotosAlbum(imageview.image, nil, nil, nil);

        // when finish, dismiss HUD
        HUD.hidden = YES;

 });
}

Answer 4

您可以使用https://github.com/samvermette/SVProgressHUD显示进度条。如果您从服务器下载图像，请使用异步调用。就像您使用ASIFormDataRequest请求获取图像一样，然后使用如下：

    [SVProgressHUD showWithStatus:@"Please wait"];
    self.view.userInteractionEnabled = NO;
    NSURL *url=[NSURL URLWithString:@"your URL request"];
    ASIFormDataRequest *request = [ASIFormDataRequest requestWithURL:url];
    [request setRequestMethod:@"POST"];
    [request setPostValue:xyz forKey:@"abc"];
    [request.shouldAttemptPersistentConnection = NO;
    request.delegate=self;
    request.timeOutSeconds = 10;
    [request startAsynchronous];

在此之后你可以打电话：

- （void）requestFinished：（ASIHTTPRequest *）请求 { NSError * error = [请求错误];

if (!error)
{

    NSString *response = [request responseString];
    NSMutableDictionary *responseJSON = [response JSONValue];
     [SVProgressHUD dismiss];
   self.view.userInteractionEnabled = YES;
    UIImageWriteToSavedPhotosAlbum(imageview.image, nil, nil, nil);

} }

希望这会对你有所帮助。

如何在保存图像光学库IOS7时添加MBProgressHUD

4 个答案: